On Thu, 2011-01-27 at 10:27 -0800, Jeremy Fitzhardinge wrote:> > So is there some way we can preserve the current scheme's benefits while> making it a bit more general? (If anyone else has non-IPI-based> shootdown, it would be s390; is there some inspiration there? An> instruction perhaps?)

Well, you can provide a xen gupf implementation based on rcu freedpage-tables like powerpc, sparc and s390 have.

But you'll have to change the mmu_gather implementation of xen and usethe get_page_unless_zero() thing mentioned before (or usepage_cache_get_speculative()).

But I see no need to change the x86 implementation, if the architectureever changes the way it does tlb invalidation we need to change morethan just the gupf implementation.